1: Look at the surface. The surface of the blockboard should be flat, without warping, deformation, blistering or depression; the core strips are arranged evenly, the gap size, whether the core strips are decayed, broken, wormholes, knots, etc. Check whether there is any glue or putty repair around.
2: Shake: Lift a corner of the board and shake it up and down to see if there is a squeaking sound of degumming or cracking. Stand the board up against the sun to see if the gap between the solid wood strips is large. If it is large, you will see white in the gap.
3: Knock: Knock the surface of the board with a pointed tool. If there is a crisp and clean sound when knocking on the surface, it indicates that the density is relatively high. If the sound is dull, the density is low. Is there any difference in the sound in different places?
4: Ask about the tree species: There are many kinds of wood panels, and softwood is mostly used, while hardwood is hard, not easy to press, has a poor splicing structure, poor nail holding force, and a large deformation coefficient. There are many woods on the market, such as poplar, birch, pine, willow, fir, paulownia, etc. Among them, birch is the best, with dense texture, neither soft nor hard wood, strong nail holding force, and not easy to deform. However, paulownia is very light, soft, absorbs a lot of water, has poor nail holding force, and is not easy to dry. When the water evaporates during use, the board is easy to crack and deform.
5: Smell: If the board emits a fragrant wood smell, it means that the formaldehyde release is less; if the smell is pungent, it means that the formaldehyde release is more.
6: Check the report: The test report will clearly state the standards, and there will be national standards for reference. The more it exceeds the national standards, the better. In terms of physical properties, there are density, moisture content, water absorption, thickness, water absorption expansion rate, etc.; in terms of mechanical properties, there are static bending strength, vertical board tensile strength (internal bonding strength), nail holding force, elastic modulus and formaldehyde emission ≤0.5mg/L, which meets the E0 standard, formaldehyde emission ≤1.5mg/L, which meets the E1 standard, and formaldehyde emission ≤0.3mg/L, which meets the US CRAB standard.